rlm_chap(5) on Linux
The text 2aec5e8a7d27, as Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch) shipped it.
FreeRADIUS Module
The text 2aec5e8a7d27, as Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch) shipped it.
FreeRADIUS Module